A High Voltage Gain Switched-Capacitor DC- DC Converter with Seven Switches for Renewable Energy Applications

Abstract

This paper presents a new concept and research results of DC-DC high-voltage-gain, high-frequency step-up resonant converters. The proposed topologies are optimized towards minimizing the number of switches and improvements in efficiency. The converter consists of seven switches, five of which being controlled like high-side type. Another relevant advantage of such type of converters is that they have a common input and output negative point. The proposed converters are based on the resonant switched-capacitor voltage multiplier circuit, and that is why they are compared with a classic converter from this family. The converter requires a special switching pattern to drive seven switches in a steady state and also during the start-up of the converter and the regulation of the output voltage. Therefore, a digital control system is used with various switching algorithms implemented. The included results show the operating principle, possible switching methods with the consideration of their impact on the voltage gain level, as well as the voltage and current ripples. The presented converter is an autonomic device that taps the energy from the main input. Therefore, the electronic system of the converter is equipped with a self-supply system with a wide range of the input voltage. The parameters of the converter such as voltage gain, voltages and power ranges can be scalable for prospective applications with the proposed control system. The operating concepts and analytical calculations are confirmed by simulation results.